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light weight rotors

12K views 25 replies 10 participants last post by  Big Sky 
#1 ·
I've been doing some research on brakes and it kinda coming up short in this area for WRXs. What is a good light weight rotor to fit in the stock rims? (I use the stock rims in the winter so they have to fit stockers)

And I know rotors don't help braking that much, I just want some light ones.

Right now my idea is :
Stock calibers
Hawk HPS pad
Goodridge Brake Lines
Some DOT4 brake fluid (any suggestions?)
and some slotted rotors. (kinda leaning to powerslot rotors)

Any specs on weights of different rotors would be awesome but I don't expect it.

(Also car is 03 WRX, daily driver that will see 1 maybe 2 track days / year and will have to deal with snow and salt)
 
#3 ·
Were you talking about the 4000 series or the 5000?

I didn't see any specs on the weight of these on the site, do you know any of that info?

I'm sure that the 5000 would be lighter (2 piece), but I can't justify spending 300/rotor unless they are extremely lighter than stock rotors.

Which bring up another point, does anyone know how much the stock rotors weigh?
 
#4 ·
weight is not really an issue with rotors, you wont even notice it! i just paid 400$ for power slot front rotors and hawk hps pads and i love the set-up! dont fuss about weight, once you get some nice rotors and pads you wont care about weight when you see how much faster you can stop your car!
 
#7 ·
Here is the whole idea that stock rotors and pads are just as good as upgraded ones:

For just a second, forget all our cars have abs. When your out driving and some idiot cuts in front of you or someone goes into your lane, you just slam on the breaks (let the abs do the rest) while steering and trying not to hit anything. The stock setup without the abs has more than enough power to lock up the tires so its not a question of how big your rotors are or how sticky your pads are; the stock setup can already do the thing that takes the most force - lock up the tires (without abs).

So then I throw my new rotors and pads on; there is no improvement in stopping distance. The new setup can do exactly what the old one could only it can do it more efficiently in that I probably don't have to push as hard on the petal to lock up the tires, but nothing really noticeable in an emergency situation.

Now add back the abs and the same thing is true; both the stock system and any upgraded system have the power to kick in the abs and make the real stopping distance that would be measured.

The benefit of the larger rotors, calibers, and pads is that they are more efficient system. More efficient means less waisted energy. Less waisted energy means less heat. Less heat means they can work longer without losing any functionality.

So when your cruising around a track and breaking really hard like every 30 sec, your breaks keep slowing you down just as quickly or close to it. When doing normal everyday driving, you generally do not reach the point where the stock breaking system starts to increase your stopping distance.

With all of that being said, that was just the general idea of it. I am sure there are many people in the forum that can give much more accurate details into what happens when your breaks start to fail from being over-stressed. I created this thread to discuss light weight rotors that can fit on the stock WRX rims. If people want to discuss the reasons why you should or shouldn't upgrade their rotors please start another thread or read about the tons of info on the subject already in these forums.

I would love the know the weight of the stock rotors other than having to take them off and weigh them myself. I would also like any suggestions and weights on rotors that are lightweight and fit under the 02-03 stock rims.

Also another question, are the Eagle HP plus pads really worth the extra $$ over the HPS ones?

And if Ian ever reads this, on that link you gave above, were you referring to the 4000 or the 5000 series dba rotors?

Thanks - YELOWRX
 
#18 ·
I created this thread to discuss light weight rotors that can fit on the stock WRX rims. If people want to discuss the reasons why you should or shouldn't upgrade their rotors please start another thread or read about the tons of info on the subject already in these forums.

I would love the know the weight of the stock rotors other than having to take them off and weigh them myself. I would also like any suggestions and weights on rotors that are lightweight and fit under the 02-03 stock rims.

Also another question, are the Eagle HP plus pads really worth the extra $$ over the HPS ones?

And if Ian ever reads this, on that link you gave above, were you referring to the 4000 or the 5000 series dba rotors?

And I know rotors don't help braking that much, I just want some light ones.

Right now my idea is :
Stock calibers
Hawk HPS pad
Goodridge Brake Lines
Some DOT4 brake fluid (any suggestions?)
and some slotted rotors. (kinda leaning to dba 4000 now)

Any specs on weights of different rotors would be awesome but I don't expect it.

(Also car is 03 WRX, daily driver that will see 1 maybe 2 track days / year and will have to deal with snow and salt)

Thanks - YELOWRX
Just a reminder on what I wanted to discuss in this thread, I've only had 1 response so far on this topic.
 
#10 ·
ok man.... i have to correct you here.... skidding increases the stopping distance.... what after market brakes decrees brake fad and makes braking more consistent.... the only things you can do to drop your stopping DISTANCE is to put wider and sticker tires on the car as previously said and also to lighten up the rotating mass aka rims.... "Light Weight Rotors" wont do anything but warp faster.... there are more effective things to do to the car to make it stop faster....
 
#11 ·
very well said, i like reading threads where people actually know what they are talking about. but back to the original discussion, i dont understand why you would want to spend pointless $ to be honest, b/c a good quality oe fittament will do the job just as well as any other rotor in that same size. to be honest with you i see so many cars come in with crossdrilled and or slotted rotors that develop premature problems such as pitting,glazing, warping not to mention they can't be resurfaced. its just not worth the extra money for certain brake components unless your pushing huge power.
 
#20 ·
I already have light weight rims and wheels that combined come in at about 3-4 lbs lighter than stock on each corner (225 wheels). And I am not going to upgrade the calibers, just rotors, pads, lines, and fluid. The reason I am changing them is that I already drive harder than the stock system will allow (warped rotors with still plenty of pad left). I also don't want to waist my money, so if there was a good set of lighter rotors (oem replacements) that cost just a little more, I would just get them. I have also heard that the stock pad are what is really holding me back, and it is probably pads overheating and "welding" residue on them that warped them. But since I warped the rotors, have to replace them too.
 
#23 ·
bout the spelling... as mosc says "Engineers can't spell, sorry!"

And trust me, these rotors need replaced...

Got the DBA 4000 series slotted rotors from Scooby Tuner.

BTW hes giving pretty good discounts in his "Everything is on sale in July" thing in the Vender's section.

I'm gonna weigh the news ones and compare them with the stockers once they come in.
 
#26 ·
oe WRX front rotors (298x24) weigh right at 14 lbs, the 4000's will actually come in ~ .5 lbs more, but that's OK more mass = good as far as rotors go. The DBA rotors wil last longer under harsh conditions (ie track days) vs oe or other "cheap" rotors due to the make up fo the rotor. There are two schol of thoughts on rotors and track days- neither wrong IMO- school of thought #1 buy high quality rotors that will last longer (ofcourse these cost more)- school of thought #2- buy the absolute cheapest rotors you can and replace them when worn- I've never done a scientific experiment to see what comes out ahead, but instead have ponied up the $ and gone w/ #1, there are lots and lots of guys that subscribe to #2 and they may well be right (cost by cost comparo)

The DBA rotors in addition to giving you longer life, also have few other advantages (albeit minor)- they are slightly over sized 295x25- this adds to the mass (as dos the unique pillar constructin).

Two piece rotors wills have shave some weight, but not a lot- the 5000's weigh 12.7 lbs- so roughly 1.5 lbs/side- the real advantage to two piece rotors is the aluminum hat dissipates heat better (quicker) whic saves on wheel bearings- the weight savings is gravy :)

They never caught on, partly due to cost, partly due to their heat properties (or lack of them), but MMC (metal matrix composite) saved significant weight over iron rotors. Carbo fiber rorts are slowly catching on- they also offer significant weight savings and are very long lived. It may not too long befoer we see these offered for "street" cars :)

Fair amount of misinformation in this thread, but I'll let the reader sort through the right and wrong :)
 
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